1. Field of the Invention
The invention relates generally to networked storage systems and more particularly to an integrated storage and switching system.
2. Description of the Related Arts
In conventional networked storage systems, storage devices typically exist as distinct components on a network that are coupled to one or more network servers via a network switch. FIG. 1 illustrates a common arrangement of a conventional storage system 100. A server rack contains up to 48 servers 102 (e.g., servers 102-1, 102-2, . . . , 102-N) coupled via links 112 (e.g., Ethernet cables) to a switch 106 for routing network traffic to and from the various servers 102 and an uplink network 104. A storage device 108 is configured externally to the server rack and communicates with the servers 202 via the switch 106 using communication links 114 (such as Ethernet cables) that have limited channel bandwidth. A typical network storage device 108 may occupy a single port (or two ports for redundancy purposes) on the network switch 106 and access to the communication link 114 coupling the storage device 108 to the switch 106 is therefore shared by a large number of servers 102 (e.g., a rack of 48 servers). As a result, each server 102 only has access to a small percentage (e.g., about 4% in a 48 rack server) of the bandwidth of the communication link 114 to the storage device 108.
In a conventional storage device 108 using relatively slow storage technology (e.g., hard disk drives), the shared bandwidth of the communication link 112 does not significantly reduce performance because the read/write speed to storage 108 is already limited by the device itself. However, with the development of substantially faster memory devices such as flash memory, the bandwidth limitations of the communication link 114 between the switch 106 and the storage device 108 can become a significant performance bottleneck.
One conventional solution simply uses higher capacity Ethernet cables 114 between the storage device 108 and the switch 106. However, this solution significantly increases the costs of the storage system 100 and is therefore undesirable. Increasing the number of cables between the switch 106 and the storage 108 is also a feasible solution, but this undesirably decreases the number of ports on the switch 106 available for the servers 102, and also adds to overall system costs.